Sealing connection for conduit couplings

ABSTRACT

A sealing connection for a pair of conduits wherein each conduit is provided with a radially outwardly directed seal ring receiving channel at its extremity in confronting relation to the other conduit. A cylindrical connector band extends between the seal rings and is confronted by a cylindrical housing, which extends thereover and is joined by a pair of pivotal connections to the two conduits to resist separation but permit limited relative angular movement. An elastomeric ring is disposed between the connector band and overlying housing to minimize angular movement or radial displacement of the connector band relative to the housing, thereby preventing excess clearance between the connector and thus prevent a seal ring against extrusion from its channel.

nite States Patent [191 Yorke et a1.

[ SEALING CONNECTION FOR CONDUIT COUPLINGS [73] Assignee: GeneralConnectors Corporation, Burbank, Calif.

[22] Filed: Apr. 13, 1972 [21] Appl. No.: 243,829

[51] int. C1. F161 21/02 [58] Field 011 Search... 285/233, 234, 261,365, 369

.[56] References Cited UNITED STATES PATENTS 3,695,636 10/1972 Graves285/233 X 2,971,781 2/1961 Torres 285/233 3,610,654 1 10/1971 Torres285/233 2,852,282 9/1958 Smisko et a1. 285/365 X 2,778,661 1/1957Leighton 285/233 X 3,462,175 8/1969 Johnson 285/369 X Jan, 22, 19743,540,758 11/1970 Torres 285/233 Primary Examiner-Jacob ShapiroAssistant Eqrqminer Davidl-l, Corbin Attorney, Agent, or Firm Lyon &Lyon [5 7 ABSTRACT A sealing connection for a pair of conduits whereineach conduit is provided with a radially outwardly directed seal ringreceiving channel at its extremity in confronting relation to the otherconduit. A cylindrical connector band extends between the seal rings andis confronted by a cylindrical housing, which extends thereover and isjoined by a pair of pivotal connections to the two conduits to resistseparation but permit limited relative angular movement. An elastornericring is disposed between the connector band and overlying housing tominimize angular movement or radial displacement of the connector bandrelative to the housing, thereby preventing excess clearance between theconnector and thus prevent a seal ring against extrusion from itschannel.

SEALING CONNECTION FOR CONDUIT COUPLINGS BACKGROUND OF THE INVENTIONReference is made to US. Pat. No. 3,540,758. An embodiment of thisinvention has been used in some passenger airplanes; however, troublehas been encountered in that the seal rings have failed by being forcedby pressure through the space existing between a connecting sleeve and aconfronting housing. That is', inspection of the coupling disclosed thatthe ring had in fact been forced, at least in part, from its channel,but the reason why this should occur was not apparent; in fact, itseemed that no reason existed for this failure, yet the evidenceexisted.

Several changes were tested but none solved the problem untildevelopment of the present invention, which on retrospect engineering itwas discovered why the original construction failed and why the presentinvention solved the problem. More specifically, it was determined thatfailure was due to:

a. tendency of the connecting sleeve to tilt increasing the clearancebetween a seal ring channel and connector sleeve;

b. the increased clearance started incipient wedging of the seal ringthrough the clearance space;

0. This force caused the connector sleeve to displace diametricallyfurther increasing the space; and

(I. still further increased space developed due to the connector sleeveto assume an oval configuration in the annulus engaged by the seal ring.

SUMMARY OF THE INVENTION The present invention is directed to a conduitcoupling joined by a sealing connection having a pair of seal rings, onefor each conduit, and a cylindrical connector sleeve, and a mechanicalswivel or pivotal connection joining the conduits and including ahousing sleeve confronting the connector sleeve; wherein an elastomericring is interposed between the housing and connector sleeves to minimizeangular movement,

DESCRIPTION OF THE FIGURES FIG. I is a sectional view of a conduitcoupling with adjacent ends of confronting conduits shown fragmentarily,the construction representing the prior art.

FIG; 2 is a fragmentary transverse sectional view thereof taken through2-2 of FIG. 1.

FIG. 3 is a sectional view corresponding to FIG. 1 but showing theimproved coupling.

FIG. 4 is a fragmentary sectional view taken through 4-4 of FIG. 3.

FIGS. 1 and 2 illustrate a conventional conduit coupling. The couplingjoins a pair of conduits 1, each having a pair of flanges 2 at its endseparated by a channel 3. The outboard flange 2 is provided with a ringof perforations 4. Axially inward from each pair of channels 2 eachconduit is provided with a spherical journal segment 5.

Each channel 3 is open radially outward and receives a seal ring 6,which may be a solid elastomeric member preferably formed of a siliconeelastomer and may contain reinforcing fabric, not shown. Extendingaxially over the seal rings 6 at a suitable distance beyond the sealrings is a cylindrical sealing sleeve 7, which is engaged by the sealrings 6.

The sealing connection formed by the sealing sleeve 7 and the seal rings6 is enclosed in a housing 8 comprising a cylindrical portion 9surrounding the sealing sleeve 7. The cylindrical portion 9 terminatesin radially inwardly directed spaced shoulders 10, which confine thesealing sleeve 7, that is, limit the axial movement of the sealingsleeve.

Continuing from the shoulders 10, the housing forms spherical bearingsegments 11 which engage the spherical journal segments 5 so that theconduits l are capable of limited pivotal movement.

The housing 8 is divided longitudinally into two complementary halveswhich aresuitably joined together by conventional means, which may takethe form shown in US. Pat. No. 3,540,758 or may involve other connectingmeans such as split retainer rings 12, the details of which are notshown as their construction may for the purposes of this application beconsidered as conventional. In fact, the entire construction thus fardescribed may be considered as conventional.

Couplings made in accordance with the above description have been usedin conjunction with the ducting systems of commercial aircraft. However,serious difficulty has been encountered due to seal ring failure; thatis, a seal ring 6 has on occasion been extruded from or otherwise forcedfrom its channel 3. The reasons for this are not entirely clear;however, it is believed that there are up to four factors which may,cumulatively, account for this failure. More specifically:

l. The sealing sleeve 7 may tilt when the conduits are disposedangularly.

2. There may be a diametrically directed transitional movement of thesealing sleeve causing the sealing sleeve to bear against a flange 2 atone side of the coupling and increase its spacing therefrom at theopposite side of the coupling. I

3. If the coupling is also subjected to substantial internal pressurewhich is applied to the channels 3 through the perforations 4, the ringmay wedge or tend to extrude into the enlarged space. This can have theeffect of producing an excess and relatively local radial load on thesealing sleeve.

4. The wedging action of the seal ring may cause the sealing sleeve toassume a slightly oval shape which further increases the spacing until apoint is reached in which the seal ring is forced from its channelcausing failure of the coupling. This excessive clearance space isindicated by 13 at the upper left side of FIG. I and in the upperportion of FIG. 2,. in which is indicated a distorted or extruded sealring portion 14.

Reference is now made to FIGS. 3 and 4. The construction hereillustrated is the same as a conventional structure shown in FIGS. 1 and2 .with the additional feature of a spacer band 15 interposed betweenthe sealing sleeve 7 and the cylindrical portion 9 of the housing 8. Thespacer band 15 may be bonded to the sealing sleeve 7 or to thecylindrical portion 9. It is preferred, however, for manufacturingpurposes to be bonded to the sealing sleeve 7. The spacer bandessentially fills the space between the sleeve 7 and cylindrical portion9 allowing for normal manufacturing tolerances. The spacer band isformed of elastomer impregnated glass fabric reinforcing laminations 16illustrated in FIG. 3. Each lamination is impregnated and coated with anelastomer, preferably a silicone elastomer capable of being bonded tometal comprising the sleeve 7 or the cylindrical portion 9.

The presence of the spacer band minimizes tilting movement of thesealing sleeve, diametrical translation movement thereof and alsominimizes any tendency of the sealing sleeve to assume an oval shape. Byminimizing these factors, the spacing between the sealing sleeve 7 andthe sealing rings 6- remain at an optimum spacing so that localizeddisplacement of the seal ring 6 from its channel 3 is prevented.

While a particular embodiment of this invention has been shown anddescribed, it is not intended to limit the same to the details of theconstruction set forth, but instead, the invention embraces suchchanges, modifications and equivalents of the various parts and theirrelationships as come within the purview of the appended claims.

We claim:

1. A means for joining a mutually confronting pair of conduits,comprising:

a. a sealing connection including means forming annular radiallyoutwardly open channels at the confronting ends of the conduits,resilient seal rings in the channels and projecting outwardly therefromand a cylindrical sealing sleeve extending over and engaging the outersurfaces of the seal rings in regions spaced outwardly from the radialouter margins of said channels;

b. a mechanical connection means including a housing sleeve having acylindrical portion extending over the sealing sleeve in radially spacedrelation thereto, and pivotal connecting units joining the end portionsof the housing sleeve to each conduit at positions axially spaced fromsaid channels away from said ends and from the axial ends of saidsealing sleeve;

c. and a band of a cylindrical reinforced elastomer,

the ends of which are axially spaced from said pivotal connecting units,said band essentially filling the space between the sealing sleeve andhousing sleeve from substantially end-to-end thereof and tending tomaintain the sleeves in concentric parallel relation upon relativeangular movements of said conduits about said pivotal connecting unitsthereby to resist diametrical translation movement and tilting movementof the sealing sleeve with respect to the seal rings, as well asdistortion of the sleeve from a cylindrical into an oval shape, therebyto minimize increase in the distance between a radially outer margin ofa channel and the confronting portion of its sealing sleeve, and retainthe seal ring in its channel.

1. A means for joining a mutually confronting pair of conduits,comprising: a. a sealing connection including means forming annularradially outwardly open channels at the confronting ends of theconduits, resilient seal rings in the channels and projecting outwardlytherefrom and a cylindrical sealing sleeve extending over and engagingthe outer surfaces of the seal rings in regions spaced outwardly fromthe radial outer margins of said channels; b. a mechanical connectionmeans including a housing sleeve having a cylindrical portion extendingover the sealing sleeve in radially spaced relation thereto, and pivotalconnecting units joining the end portions of the housing sleeve to eachconduit at positions axially spaced from said channels away from saidends and from the axial ends of said sealing sleeve; c. and a band of acylindrical reinforced elastomer, the ends of which are axially spacedfrom said pivotal connecting units, said band essentially filling thespace between the sealing sleeve and housing sleeve from substantiallyend-to-end thereof and tending to maintain the sleeves in concentricparallel relation upon relative angular movements of said conduits aboutsaid pivotal connecting units thereby to resist diametrical translationmovement and tilting movement of the sealing sleeve with respect to theseal rings, as well as distortion of the sleeve from a cylindrical intoan oval shape, thereby to minimize increase in the distance between aradially outer margin of a channel and the confronting portion of itssealing sleeve, and retain the seal ring in its channel.